1. Field of Invention:
The invention relates to mounting structure for a vehicle bumper assembly which permits desired positionment of the bumper assembly with respect to the main vehicle structure while taking into account minor dimensional variations in the vehicle build.
2. Prior Art:
Government regulations have mandated that front and rear bumpers of vehicles be so constructed and mounted as not to be damaged as a consequence of low speed impact with other vehicles or fixed structure. The prevailing method for accomplishing this is to mount the bumper onto a vehicle by means of an energy absorbing device, such as a shock absorbing structure. When the bumper is impacted at low speeds, the energy absorbing device collapses, absorbing the energy of impact. This collapse takes with it the bumper which moves towards the vehicle. After being impacted, the energy absorbing devices bias the bumper back to its normal position.
One problem which has been encountered in connection with the mounting of vehicle bumper assemblies including energy absorbers has been proper alignment of the bumper assembly with other portions of the vehicle. When a vehicle is assembled, there is normally a minor dimensional variation from the norm. This is due to the fact that a vehicle build includes many interfitting parts. This problem has been particularly acute with respect to alignment of the end portions of the bumpers with fender structure of a vehicle. Modern perceptions of "fit and finish" do not permit the existence of any substantial gaps between adjacent outer body panels. One method for adjusting the positionment of the bumper has been the use of shims between the energy absorbers and the bumper structure. This technique is discussed in U.S. Pat. No. 4,160,561, entitled "Vehicle Bumper Shim and Method".
Another technique which has been employed to eliminate the appearance of a gap between the bumper structure and vehicle fenders has been to provide a flexible panel portion on each end of the bumper. This flexible portion has been long enough to extend slightly over the adjacent vehicle fenders so that even if the bumper structure is not close enough to the fenders to prevent the presence of a gap, the gap is covered by the overlapping panel structure. This is objectionable from a style standpoint because it adds an extra vertical line to the vehicle body structure which is not part of the coordinated design intended by the stylist. Alternately, over-lap has been avoided by directly attaching the flexible panels to the fender. However, this has sometimes resulted in objectionable appearance (wrinkles or bulges) or has required a floating attachment of the bumper facia to a bumper beam.
An alternate means for mounting the bumper assembly by use of support structure including threaded means which permit forward or rearward adjustment of the bumper assembly as desired has been proposed, as for example in U.S. Pat. No. 4,770,453. While such a technique is useful, the adjustment is possible in one direction while unfortunately dimensional variation in vehicle build is three dimensional.
The present invention provides a means for mounting the bumper assembly which accommodates three dimensional variations in vehicle build. This is accomplished by the use of elongated mounting slots, enlarged openings and oversize mounting bracket structure.